This invention generally pertains to design patterns for opaque articles. More specifically, this invention relates to at least two design patterns used on the surface of a opaque article, the patterns each comprising pluralities of parallel ridges oriented to yield a striking visual appearance.
The invention is particularly applicable to the black sidewalls of rubber tires. However, it will be appreciated by those skilled in the art that the invention has broader applications and may be employed in the manufacture of rubber mats or various other opaque articles.
Manufacturers have for many years placed numerals, letters, characters or other designations upon the sidewalls of tires to enhance the appearance and marketability of their products. Such markings are described in U.S. Pat. Nos. 4,198,744 and 4,823,856.
The subject matter of U.S. Pat. No. 4,198,774, issued Apr. 22, 1980, was invented by Roberts and Lowther. The invention describes the use of lineal projections which are substantially straight, parallel, and of substantially identical cross-section to form indicium. An indicium is described as a letter or numeral or the like.
The latter issued patent of Mr Charles W Roberts, U.S. Pat. No. 4,823,856, issued Apr. 25, 1989, describes the use of serrated outline markings for the sidewall of a tire. The invention relates to a design of a substantially flat ungrooved portion surrounded by a serrated portion which includes a plurality of ribs separated by grooves. The combination of the flat design surrounded by a serrated portion defines an indicium.
The present invention employs the use of at least two distinctive design patterns which improves the visual appearance of an opaque article by increasing the visual contrast of the surfaces of articles. The invention is particularly well-suited for the sidewall of a tire, particularly a black sidewall tire. The combination of design patterns in at least one embodiment of the invention, has the effect of making the sidewall markings boldly stand out when viewed from an angular perspective of 60.degree. or less relative to a plane parallel to the sidewall wall of the tire. The design patterns uniquely change in contrast relative to each other in an inverse relationship as a function of the position of the tire.